Aziridine, also referred to as ethyleneimine, has found a wide application in the fields of medicine, pesticide, high-energy fuel, bonding agent, photographic material, crosslinking agent, and the like. Piperazine is an important pharmaceutical intermediate and a fine chemicals raw material. Triethylenediamine is one of the most important polyurethane catalysts.
A preparation method for ethylenimine by using the complex oxide of a niobium oxide or a tantalum oxide and an alkaline earth oxide (BaO) as a catalyst is disclosed in U.S. Pat. No. 4,337,175. By using monoethanolamine (MEA) as the raw material, the preparation method was carried out in the presence of NH3 as inert protective atmosphere at the temperature of 390° C. to 400° C., and as a consequence, the MEA conversion was 13.87% with selectivity to ethylenimine of 82.09%. Further, a small amount of acetaldehyde, ethylene amine, pyrazine and alkylpyrazine were also generated.
A silicon-containing catalyst with an elemental composition of Sia/Xx/Yy/Ob is disclosed in EP0227461, wherein X is any element selected from alkaline metals or alkaline earth metals; Y is at least one element selected from the group consisting of B, Al, Ti, Zr, Sn, Zn, and Ce; the suffixes a, b, x, and y represent the atomic ratios of the elements Si, X, Y and O respectively, and when a=1, x=0.05˜1 and y=0˜0.1, and b is a value determined by a, x and y. By using monoethanolamine as the raw material, an inert gas (such as NH3, N2 or H2) as a diluent, and the ratio of ethanol amine to the inert gas being 2˜50%, the reaction was generally carried out under atmospheric pressure at the temperature of 300° C. to 500° C., with the optimum space velocity of the reactant gas of 500 to 3,000 h−1. As a consequence, the optimum conversion (mol) of ethanolamine was 56.5%, the selectivity (mol) to aziridine was 89.1%.
In the prior arts, the raw materials such as monoethanolamine, diethanolamine, ethylenediamine, aminoethyl piperazine, and hydroxyethyl piperazine are generally used in the production of piperazine and triethylenediamine.
A production of triethylenediamine using surface acidity deactivated zeolite catalysts is disclosed in CN97123116.8. By using monoethanolamine and piperazine as reaction materials, the reaction was carried out at 350° C., with the liquid hourly space velocity of 0.52 h−1. As a consequence, the conversion (mol) was 72%, and the selectivity (mol) to TEDA was 30%.
New approaches for aziridine, piperazine and/or triethylenediamine are provided in the abovementioned documents. The reactions are acid catalyzed reactions, and solid acid catalysts may be used. However, the catalysts used in the above methods differ greatly, so that aziridine, piperazine and/or triethylenediamine cannot be produced jointly and simultaneously in a same device.
No reference document, in which a joint production method for aziridine, piperazine and triethylenediamine by using ethanolamine as a raw material is disclosed, is searched.